I would recommend you check his website as well. He has supporting materials and text to go with videos. One warning on videos dealing with DTB overlays: the dtc tool that ships with Angstrom isn’t the same as Ubuntu. For one thing there is no -@ option.
Absolutely - his site, and his YouTube site have additional information, fixes, etc., submitted by him and his readers and I read them very carefully!
However, with respect to supporting materials, these appear to be more complete for later videos than for earlier ones. I am certainly not trying to “out do” Prof. Malloy, just posting my work to make it easier for somebody to follow the same path I did.